Polymerization of β-lactones under rim conditions

Abstract

A method is disclosed for making a molded article of manufacture of polymerized beta -lactone which method involves injecting into a mold at least one beta -lactone monomer and at least one nucleophilic initiator, substantially polymerizing the beta -lactone in the mold and removing the resultant polymerized article from the mold.

What is claimed is: 
     
       1. A method for making a molded article of manufacture comprising polymerized β-lactone which method comprises injecting into a mold at least one β-lactone monomer and from about 1.0×10 -8  to about 1.0×10 -1  by weight basis monomer of at least one nucleophilic initiator, polymerizing said β-lactone in said mold and removing the resultant polymerized article from the mold. 
     
     
       2. The method of claim 1 wherein the β-lactone has the formula: ##STR5## wherein R 1 , R 2 , R 3  and R 4  are individually hydrogen or hydrocarbyl of carbon number ranging from 1 to about 20. 
     
     
       3. The method of claim 2 wherein R 1 , R 2 , R 3  and R 4  are individually hydrogen or hydrocarbyl of carbon number ranging from 1 to about 6. 
     
     
       4. The method of claim 3 wherein the β-lactone monomer is selected from the group consisting of propiolactone, β-butyrolactone, pivalolactone and mixtures thereof. 
     
     
       5. The method of claim 1 wherein the nucleophilic initiator is one or more organic compounds of Group Va of the Periodic Table. 
     
     
       6. The method of claim 5 wherein the nucleophilic initiator is one or more compounds selected from the group consisting of amines, phosphines, arsines, stibenes, bismuthenes and mixtures thereof. 
     
     
       7. The method of claim 6 wherein the nucleophilic initiator has the general formula R 1  R 2  R 3  Z wherein Z is nitrogen or phosphorus and R 1 , R 2  and R 3  are hydrocarbyl of 1 to 10 carbon atoms. 
     
     
       8. The method of claim 6 wherein the nucleophilic initiator is selected from tertiary amines, tertiary phosphines and mixtures thereof. 
     
     
       9. The method of claim 1 wherein the initiator comprises from about 1.0×10 -7  to about 1.0×10 -2  mole % of monomer. 
     
     
       10. The method of claim 9 wherein the initiator comprises from about 1.0×10 -6  to about 1.0×10 -3  mole % of monomer. 
     
     
       11. The method of claim 1 wherein said mold is maintained at a temperature of from about 60° C. to about 120° C. prior to injection of monomer and initiator. 
     
     
       12. A polymer article of manufacture produced according to the method of claim 1 having a molecular weight of at least 20,000 as determined by low angle laser light scattering. 
     
     
       13. The polymer article of manufacture produced according to the method of claim 12 having a molecular weight of at least 30,000. 
     
     
       14. A polymer article of manufacture produced according to the method of claim 1 having crystallinity of greater than about fifty percent. 
     
     
       15. The polymer article of manufacture produced according to the method of claim 14 having a crystallinity of greater than about sixty percent. 
     
     
       16. The polymer article of manufacture produced according to the method of claim 16 having a crystallinity of greater than about seventy-five percent. 
     
     
       17. A method for making a molded article of manufacture comprising polymerized β-lactone which method comprises injecting into a mold at least one β-lactone monomer of the formula: ##STR6## wherein R 1 , R 2 , R 3  and R 4  are individually hydrogen or methyl and from about 0.01 to about 1 percent by weight basis monomer of at least one nucleophilic initiator selected from tertiary amines or tertiary phosphines, polymerizing said β-lactone in said mold and removing the resultant polymerized article from the mold. 
     
     
       18. The method of claim 17 wherein said initiator is selected from a compound having the general formula R 1  R 2  R 3  Z wherein Z is nitrogen or phosphorus and R 1 , R 2  and R 3  are hydrocarbyl of 1 to 10 carbon atoms. 
     
     
       19. The method of claim 17 wherein said mold is maintained at a temperature of from about 60° C. to about 120° C. prior to injection of monomer and initiator.